Stuck with a quest

An NPC in the refugee center sent me on a quest to kill some bandits. I killed them but the quest marker will not move back to the questgiver. Nor is there the option to report success if I go back to him.

I even reloaded and ensured that they saw me and triggered into hostility, and that it was I who killed them (they have a propensity to destroy each other with stray bullets). No dice.

The quest is called Missing Caravan.


Update: Apparently loading a game that was saved with a quest active will break the quest.

It works if you do it in one go.